IEMbase 0762: DDHD2-related phosphatidic acid-preferring phospholipase 2 deficiency
Scope
| Field | Value |
|---|---|
| IEMbase ID | 762 |
| Nosology | 14.5.01.11 |
| Nosology code | IEM0671 |
| Gene | DDHD2 |
| External IDs | OMIM:609340; ORPHA:320380 |
| Generated mapping | UNMAPPED; weak candidate ALDH18A1_De_Barsy_Spectrum.yaml |
| Candidate DisMech targets | None exact |
| Review date | 2026-07-08 |
IEMbase phenotype signal
IEMbase labels this autosomal recessive record as DDHD2-related phosphatidic acid-preferring phospholipase 2 deficiency, with alternate name autosomal recessive spastic paraplegia type 54. The phenotype rows describe a childhood through adult neurodevelopmental and motor syndrome: developmental delay, behavioral disorder, microcephaly, spastic paraparesis, pyramidal signs, bulbar dysfunction, abnormal eye movements, brainstem atrophy, cerebellar atrophy, cerebellar white matter abnormalities, corpus callosum hypoplasia, and syrinx.
DisMech phenotype coverage
No exact DDHD2 / SPG54 entry is present locally. The generated
ALDH18A1_De_Barsy_Spectrum.yaml candidate is a false positive. That entry
models ALDH18A1 / P5CS deficiency with SPG9A/SPG9B and neurocutaneous disease,
not DDHD2 phospholipase deficiency or SPG54.
Concordance and completeness
Judgement: true local gap.
The IEMbase record should be curated as a distinct DDHD2 hereditary spastic paraplegia entity. The local ALDH18A1 entry shares broad spastic-paraplegia vocabulary but has different gene, biochemical mechanism, subtype identity, and expected amino-acid metabolism context.
Curation actions
- Add a distinct DDHD2 / autosomal recessive spastic paraplegia type 54 target before treating this record as covered.
- Reject
ALDH18A1_De_Barsy_Spectrum.yamlas exact coverage. - Review the duplicated OMIM value in the local IEMbase cache before modeling identifiers, because the source record repeats the DDHD1 OMIM value.